Modern computer systems place a high importance on security of user access to computing resources. Specifically, the security of network communications is important to both network users and network service providers. One way that the security of network communications is enhanced is through the use of digital certificates. A digital certificate is an electronic document that can be used to prove the identity of the certificate owner by showing ownership of a public key. However, maintaining the security of digital certificates can be difficult and consume significant resources. For example, certificate authorities use robust verification processes to ensure that certificates are not issued in error. Nevertheless, an attacker may attempt to obtain a counterfeit digital certificate and impersonate another company, user, or entity. Accordingly, a client computing device that receives a digital certificate in response to a request to access a computing resource may also want to perform operations to ensure that the digital certificate is trustworthy.